Draft-control device



June 1 1926;

' F. E. MCVAY DRAFT CONTROL DEVICE Filed Feb. 20, 1926 2 Sheets-Sheet 1 June 1 F. E. M VAY DRAFT CONTROL DEVICE Filed Feb. 20, 1926 2 Sheets-Sheet 2 Patented June 1, 1926.

UNITED STATES FRANCIS E. MOVAY, OF PA'WTUCKET, RHODE ISLAND.

DRAFT-CONTROL DEVICE.

Application filed February 20, 1926. Serial No. 89,754.

This invention relates to draft control devices and more particularly to draft controls for steam or hot water household furnaces.

An important object of the invention is to provide a device of this character which is automatic in its operation and which may be very readily and cheaply applied to the furnace.

A further object of the invention is to provide a device of this character whereby a proper relation is maintained between the drafts at all times, thus preventing overchecking or underchecking of the fire in response to an increase in pressure-or temperature within the furnace.

A further and more specific object of the invention is to provide a device of this character which will permit the draft to be removed from the furnace without fully checking the furnace and will permit the furnace to be partially checked by the ordinary.flue damper without checking the same at the coal check or door openings of the furnace.

A further object of the invention is to provide a device of this character which may be readily adjusted to suit the needs of 133118 particular furnace to which it is aplie p These and other objects I attain by the construction shown in the accompanying drawings, wherein for the purpose of illustration is shown a preferred embodiment of my invention and wherein Figure 1 is a side-elevation of a furnace provided with controls arranged in accordance with. my invention;

Figure 2 is an enlarged detail view of the rear end of the arm. showing the connections to the smoke pipe check;

Figure 3 is a section on the line 3-3 of Figure 2;

Figure 4 is a detail front elevation of the door showing the connections employed for the slide controlling the door check;

Figure 5 is a section on the line 5-5 of Figure 4;

Figure 6 is a detail side elevation of the upper portion of the furnace showing how the spring 29 removes the slack from the connections with the door check.

Referring now more particularly to the drawings, the numeral 10 generally designates a furnace having the usual under draft 11, flue check 12 and fire door check 13. The flue check 12 is biased, as by a counterweight 14 to normally maintain the same in closed or operative position while the fire door check 13 is biased, as by a spring 15 to normally maintain the same in inoperative position in which a slide 16 closes the openings 17 of the fire door.

In accordance with my invention, I provide a lever 18 suitably pivoted, as at 19,

upon the furnace and having connections 20, 21, 22 with the under draft 11, flue check 12 and fire door check 13. These connections are such that the draft 11 may be closed slightly before sumes its closed position and both the draft 11 and flue check 12 may be fully closed .before the fire door check 13 is effected.

The connection between the lever 18 and the draft 11 is in the form of a link pivotally connected to the draft door 23 and to the lever 18 at the end thereof adjacent the flue check 12, this link being formed in two slidably connected sections 24 and 25.

The connection 21 between the flue check 12 and the lever 18 is in the form of a flexible element, such as a chain. which permits a predeterminedelevation of the adj acent end of the lever before any movement of the flue check is effected. In the present instance, this connection is shown as tightening when'the lever 18 is horizontally disposed and is exercising a pull to check 12 as the adjacent end of the lever moves upwardly from its horizontal position.

The connection 22 between the lever and the fire door check 13 is connected with the lever at the opposite side of the pivot 19 from the connections and 21. This connection includes a bell crank lever 26 pivoted to the fire door and having one arm thereof connected with the slide 16, as at 27. The opposite arm is connected with the lever 18 by a chain 28 of such length that the chain becomestaut as the lever arrives at that position in which the flue check 12 is fully closed. In order to prevent slack in the chain from becoming looped about the end of the lever 26, when the end of the lever to which the connection is made is depressed, a light spring 29 is connected between spaced links of the chain so that this slack is taken up. This spring, as the. lever shifts, will extend to permit the chain to tighten so that operation of the slide 16 may be efl'ected. The lever 18 is engaged at that side of the pivot to which the connection 22 is made the flue check 12 as open the I by an expansion device 3% which may be either e pressure responsive device it furnace is empioyed with steam or e thermostatic element if hot water is empioyeoin This enci of the iever is also provicieti With en e justehie counterweiw it 31 tor reguhe pressure or tem ereture which the iever is shiifteoi .cy the expansion eiev the ooeretion or "re cievice f if" tem ire or ssure the expansion eieinent 8C- ivfli evete the orward e116; oi the ievei' 1 he resuit that the draft door is ciosee; and one or flue check nertiaiiy cioseciyv It the temperature continues 5o rise, i e oiemper continues to LA! move to its cioseci position and iineiiy er- :ives at iis cioseci position If this 'Eeiis to check the 1 :1 7 continued operation oi the lever Wiii cause siicie 16 to he moveci to oosition with the result that the ire err 13 is brought into operation,

1, or" course he understood that the construction hereinhefore set :iorth is obviousiy cenehie o' e certain range of change end modification Without materially deport; ing; from the spirit of the invention i eccorriingiy do not limit myseh to such specific structure except as hereinafter cioimeci.

- combination with o furnace inciuol: he usuei uncier emit, a flue checir hieseoi eintain the some in cioseci position and LG olooicheeir having the usuei siide, the s do being biased to maintain the some in closed position e- ;oivoteci i ver and connections between seici lever and the under draft, flue check and fire door check whereby continued movement of the lever in one direction consecutiveiy closes the under cireit, operates the hue check enci opens the siioie of the fire door check.

In combination with a furnace includingthe usual under draft, a flue check biased to maintain the some in ciosedl position emit a fire door check having the usuei siide, the

ehde being hissed. to maintain the some ciosed positiom e pivoted lever, connections etWeen seiti lever the unoier omit,

neck enoi fire door check whereby conti.

e incl the ueuei unuer (ire/rt o iiue check Glad to maintain the same in ciose e s n o o fire doorchecir having the usuzii siicie siicie being" 'oieseci to marine n the some in CiOSQ(i position, a pivoted lever and connections between said iever the J; or jheit Hue check and fire door check where continued movement oi? the lever one re ction consecutive; cicses the under u operates the flue check and ooens the the fire door check, the nmement iever in the opposite direction the fire door check to he completely closed 31v under eie influence oi its bias herore the fiue check is shifted,

i combination W'th e t unece inc" the usual under em a hue check or s tain the some in cioseo. position ind e door check having the usuai slide, the shoe being hieseci ma tain the so e ciosed position er and c tions between seioi lever and the under emu, flue check and fire cioor check whereby conto tinueci movement oi L e lever in one direction consecutively closes the under draft, operates the fine check and opens the slide 0' door check, the movement oi he the opposite direction permitting the ire (i001- check to he compieteiy closed under the influence 0]: its hies before the fine checir is shifteci and partieiiy opening seiti fine check before the under draft is openeci.

in testimony 'vvhereof i hereunto the his 

